Before answering your Questions, I'd like to explain my point of view by answering other questions.
Does Islam allow slavery?
The short answer is:Yes Islam allows slavery!
It is worth pointing out that you do not find any text in the Qur’aan
or Sunnah which enjoins taking others as slaves, whereas there are
dozens of texts in the Qur’aan and the ahaadeeth of the Messenger
(peace and blessings of Allaah be upon him) which call for manumitting
slaves and freeing them. (taken from my reference islamqa)
The Details: In the Time of the Messenger of Allah (peace be upon him) slavery was something ordinary. Islam considered it as a temporal necessity which vanishes when its reasons/circumstances disappear. Therefore Islam gave laws and rules for Muslims about slavery including the following matters:
- Which kind of slaves are allowed: we know that only prisoners of war can be taken as slaves
(note even in this case there are details: for example instead of enslavement the ruler could ask for ransom, or free them if this would be a benefit for Muslims and yes also killing could be an option)
and here we also know if they declare "Islam" they won't be taken as slaves. And the Muslims at least could choose to free their prisoners of war etc.! An other possibility is to be born as a child of slaves in a Muslims household.
- Islam doesn't allow a Muslim to enslave a Muslim: Muslims can't in any case make a Muslim or (at least) one of the people of the book who live beside them a slave! But in medieval Europe a defaulter or debtor etc. could be made slave for his obligee/creditor! And prisoners of war no matter if they where Christians or Jews or anything else could be made slaves!
- Rules how to treat a slave!
- The rights of a slave: For example one can't force a slave to do something bad or a sin:
But let them who find not [the means for] marriage abstain [from
sexual relations] until Allah enriches them from His bounty. And those
who seek a contract [for eventual emancipation] from among whom your
right hands possess - then make a contract with them if you know there
is within them goodness and give them from the wealth of Allah which
He has given you. And do not compel your slave girls to prostitution,
if they desire chastity, to seek [thereby] the temporary interests of
worldly life. And if someone should compel them, then indeed, Allah is
[to them], after their compulsion, Forgiving and Merciful.
[Surat an-Nur (24:33)]
This Verse also shows that one could (is encouraged to) write a contract to free a slave or make contracts with slaves.
About the revealing of the last part of the verse It's narrated that a slave-girl (which according some narration has converted to Islam) was forced to do zina (after her conversion) and before coming to Medina she was used to do so.
Jabir reported that 'Abdullah b. Ubayy b. Salul used to say to his
slave-girl: Go and fetch something for us by committing prostitution.
It was in this connection that Allah, the Exalted and Glorious,
revealed this verse:" And compel not your slave-girls to prostitution
when they desire to keep chaste in order to seek the frail goods of
this world's life, and whoever compels them, then surely after their
compulsion Allah is Forgiving, Merciful"
[Sahih Muslim and in a Version in Sunan abi Dawod the slave girl was
- Many expiation for sins where one could choose or has to free a slave.
- Islam encouraged to free slaves:
Zakah expenditures are only for the poor and for the needy and for
those employed to collect [zakah] and for bringing hearts together
[for Islam] and for freeing captives [or slaves] and for those
in debt and for the cause of Allah and for the [stranded] traveler -
an obligation [imposed] by Allah . And Allah is Knowing and Wise.
see also in sahih al-Bukahri and Muslim.
- If a man harm his slave the slave becomes free
'Amr bin Shu'aib narrated from his father that his grandfather said:
“A man came to the Prophet (ﷺ) screaming. The Messenger of Allah (ﷺ)
said to him: 'What is the matter with you?' He said: 'My master saw
me kissing a slave woman of his, so he cut off my penis.' The Prophet
(ﷺ) said: 'Take me to the man.' He was sought but could not be found,
so the Messenger of Allah (ﷺ) said: 'Go, for you are free.' He said:
'Who will protect me, O Messenger of Allah (ﷺ)? What if my master
enslaves me again?' The Messenger of Allah (ﷺ) said: 'Your protection
will be (incumbent upon) every believer or Muslim.'”
[Sunan ibn Majah and a more detailed Version in Sunan abi Dawod]
- We also have rules about relationships (intercourse/marriage) to female slaves (See for example: Shouldn't a slave woman guard her private parts except from her spouse?):
- a Muslim master could have intercourse with a female slave (he owns) under some conditions (For example a slave woman could reject her master for reasons like illness etc.!), but a Muslim woman is prohibited to have intercourse with a male slave.
- A Muslim man could marry a female slave owned by an other Muslim man.
- Apparently female slaves which are kufar, worship idols or polytheists are haram for this purpose, but there are opinions allowing it, for example ibn 'Abd al-Barr said that the hadiths (like this one) which show that Muslims had intercourse with pagan captives have been made void by verse 2:221
And do not marry polytheistic women until they believe. ...
so this is the prevalent opinion according this fatwa (in Arabic), while this fatwa (in Arabic) uses one of the given ahadith as a proof to allow it.
- No Muslim man could have intercourse with a female slave if the property (of the slave) is joint (see for example here in Arabic). A slave falls into the property of it's new owner more or less the same way as for marriage it needs: two witnesses and the approval of the former owner or the authority (for example in case of a war the "General" who has distributed the war booty).
- A Muslim man if having a relationship with one of his slaves, has to take in account that her sisters/mother etc. are automatically mahram for him as it would be with a free wife! Of course he couldn't have intercourse with a slave which is one of the haram relatives of his own.
- Some scholars say that a Muslim master has no sexual rights over a married slave (this is generally based on 4:24, as a captive could have been at least before her captivity somebody's legal wife)!
- If a female slave which was a concubine of her master give birth to a child from him (that means if this child at least cries once, it doesn't need to stay alive) she is automatically free if her owner dies, the owner is prohibited to sell her and she would have less duties than any other slave!
- Islam encourages Muslims to free their slaves if they convert to Islam!
- Muslims are also allowed and encouraged to marry their former slave woman by Quran (for the case of a man who can't afford the conditions to marry a free woman) and sunnah.
From this we can conclude that it's not a goal of Islam to maintain slavery!
Some useful links (mostly in Arabic):
How about today?
Most scholars today when being asked about slavery or mulk al yamyn and the rights of woman slaves etc. react by saying that they think that slavery nowadays doesn't exist (even in the form of a prisoner of war because of international agreements) and that the one who pretends having a slave should check well if the country his slave comes from is still allowing slavery as most Muslim countries reject slavery officially.
This means most of them consider these questions as a theoretical/hypothetical question and if the questions includes information that a man nowadays has a kind of slave they would ask him to do repentance/expiation etc.
Now to your question:
Are Muslim men allowed to take sex slaves?
If sex slaves means that the female slave would be harmed or raped or asked to do zina (having intercourse with different men) the answer will clearly be no as you can conclude from above!
In any other case it is allowed to have a concubine but with conditions as we can conclude from above (is the slave married/is she a polytheist...), that means if the conditions are fulfilled and the Muslim man theoretically could have intercourse with the female slave he has the right to do so!
But as I mentioned nowadays this isn't possible as we have international contracts and therefore Muslims can't make prisoners of war and therefore not have any kind of slaves!
And Allah knows best!